When Dad and Dr. Herb Aldwinckle began their apple rootstock breeding program  40 years ago, they had no idea that they would be evaluating more than 300,000 hybrid seedlings, all derived from careful hand pollinations.  Now they've introduced new rootstocks that have survived Dr. Aldwinckle's massive inoculations with the Phytophthora (collar rot) fungus and with fire blight bacteria and have come through Dad's testing in layerbed, nursery and orchard.  

    Burrknots have long been a serious problem with the Malling and Malling-Merton rootstocks, and a related problem has  wiped MARK® off the rootstock roster.  The burrknot problem is genetic, not caused by pathogens, and the Geneva team has been screening rigorously against them.  This has not completely eliminated burrknots, but it does seem to have eliminated the burrknot problem..  (Unfortunately, this anti-burrknot selection has made propagation much more difficult!!)

          More new rootstocks are on the way from Cornell, including some with incredible production efficiency ratings.  Since Dad retired, Dr. Terence Robinson has taken on responsibility for the orchard testing of advanced selections and Dr. Gennaro Fazio is the new USDA apple rootstock breeder.    At the top of the list, now being introduced,  are CG.3041, CG.5202 and CG.5935.  CG.3041 will be challenging Malling 9 -- full dwarf, a bit more dwarfing than M.9; productive; better anchorage; fire blight resistant; fairly good resistance to woolly apple aphids (WAA)  .  CG.5202 and CG.5935 will challenge Malling 26;  both have good fire blight resistance.  CG.5202 has been  introduced primarily for New Zealand, Brazil, South Africa and Australia, where the woolly apple aphid is a critical problem.  Trees on CG.5935 are extraordinarily precocious and productive;  we think this stock will be especially valuable under varieties like Northern Spy and Golden Russet.

        As Cornell-licensed propagators, Cummins Nursery will continue to be at the forefront in introducing new rootstocks to the grower.  We have Geneva 11®, Geneva 16®  and Geneva 30® in production  now.  We've been offering finished trees grafted on the Geneva stocks since 1999.

        Six years ago we dug our first trees on Geneva 16 -- just a few dozen, all gone out for testing.  Geneva 16 may be the rootstock for which the industry has been waiting.  In the test orchards in West Virginia and here in New York, trees on G.16 have been  smaller than those on Malling 26, about the same as those on M.9EMLA .  The Geneva 16 picture is clouded because G.16 is very sensitive to the common viruses that are transmitted in "dirty" scionwood.  Many varieties, like Crimson Jonagold®, Fortune®, Binet Rouge, and most Gala strains,  carry these latent viruses, so we're very cautious to be using clean scionwoodl  One unexpected bonus for Geneva 16:  we have had 3 customer reports from the Southeast that trees on G.16 have survived severe drought conditions better than any other stock tried.

Geneva 65® -rooted trees will be available on very limited scale in 2012.  G.65 is considerably more dwarfing than M.9 -- same level as M.27  Two big problems:  it's almost impossible to root in the stoolbed; and it sets such heavy crops that fruit size has consistently been small. 

    We've been propagating the new Geneva 11® as fast as we can by conventional (non-tissue culture) methods -- nurse-root-grafting, cuttings, and layering -- but it is a slow process.  We're working on some new propagation methods too, that we hope will accelerate the process.  I'm especially enamored with Geneva 11® -- it makes what I think is just the right size of tree -- just a little smaller than M.26.  We have about 1500 layer-mother plants of Geneva 11® growing now and  serious production has started.  Geneva 11® is not as resistant to fire blight as the rest of the Geneva rootstocks, but it is much less sensitive than M.26.  We have stuck to conventional propagation of Geneva 11® because of concerns about burrknots;  G.11® does have a slight tendency to burrknot production, and we think that any tissue-culture manipulation will make that situation a lot worse. 

    Geneva 30® continues to challenge Malling 7;  although semidwarfing, G.30 is somewhat brittle (more so than M.7) and under Gala and similarly brittle varieties should be staked.  G.30 also tends to throw suckers, about as much as M.7.  But the bottom line is that every variety we've tested is much more productive on G.30 than it is on M.7.  

    Cornell-Geneva Rootstocks for Other Species:  On Dad's back-burner during his Cornell years, he was working toward new stocks for pears, peaches and cherries.  He had made  number of crosses among the Old Home x Farmingdale rootstocks, screened them for resistance to Phytophthora and fire blight, and had commenced some orchard testing.  He was looking for hardier rootstocks for peaches and had some red-leaved selections from the Rutgers Redleaf X Siberian C family.  These candidates have disappeared over the years since his retirement.  He did introduce 3 super-dwarfing rootstocks for cherry -- FR-1, FR-5 and FR-6, all selections of Prunus fruticosa, the Mongolian bush cherry.  These have some serious problems, especially excessive suckering and difficult propagation, but they do appear to be interesting toys.